H48: Using ol, ul and dl for lists or groups of links

Important Information about Techniques

See Understanding Techniques for WCAG Success Criteria for important information about the usage of these informative techniques and how they relate to the normative WCAG 2.0 success criteria. The Applicability section explains the scope of the technique, and the presence of techniques for a specific technology does not imply that the technology can be used in all situations to create content that meets WCAG 2.0.

User Agent and Assistive Technology Support Notes

Description

The objective of this technique is to create lists of related items using list elements
appropriate for their purposes. The ol element is used when the list is
ordered and the ul element is used when the list is unordered. Definition
lists (dl) are used to group terms with their definitions. Although the use
of this markup can make lists more readable, not all lists need markup. For instance,
sentences that contain comma-separated lists may not need list markup.

When markup is used that visually formats items as a list but does not indicate the
list relationship, users may have difficulty in navigating the information. An example
of such visual formatting is including asterisks in the content at the beginning of each
list item and using <br> elements to separate the list items.

Some assistive technologies allow users to navigate from list to list or item to item.
Style sheets can be used to change the presentation of the lists while preserving their
integrity.

The list structure (ul/ol) is also useful to group hyperlinks. When this is done, it helps screen reader users to navigate from the first item in a list to the end of the list or jump to the next list. This helps them to bypass groups of links if they choose to.

Examples

Example 1: A list showing steps in a sequence

This example uses an ordered list to show the sequence of steps in a process.

Example Code:

<ol>
<li>Mix eggs and milk in a bowl.</li>
<li>Add salt and pepper.</li>
</ol>

Example 2: A grocery list

This example shows an unordered list of items to buy at the store.

Example Code:

<ul>
<li>Milk</li>
<li>Eggs</li>
<li>Butter</li>
</ul>

Example 3: A word and its definition

This example uses a definition list to group a definition with the term that is
being defined.

Example Code:

<dl>
<dt>blink</dt>
<dd>turn on and off between .5 and 3 times per second
</dd>
</dl>

Example 4: Contact information using a definition list

This example uses a defintion list to mark up pairs of related items. The pairs themselves are a logically related list. Since browsers lack wide support for CSS styling on definition list elements, span elements have been included in the markup for styling purposes only, and are not required:

Related Techniques

Tests

Procedure

Check that content that has the visual appearance of a list (with or without bullets) is marked as an unordered list.

Check that content that has the visual appearance of a numbered list is marked as an ordered list.

Check that content is marked as a definition list when terms and their definitions are presented in the form of a list.

Expected Results

All the checks above are true.

If this is a sufficient technique for a success criterion, failing this test procedure does not necessarily mean that the success criterion has not been satisfied in some other way, only that this technique has not been successfully implemented and can not be used to claim conformance.